206 research outputs found
Asia and World History : The State and the Intellectuals
2)This article was intended, at The International Symposium of 1994 held by the Department of Sociology, Hosei University. Until recently, Far East Asia was believed one huge continental region underdeveloped overall. In fact, this was not true. Under close scrutiny, it had been, in a way, highly interconnected regions under a patronus-clientes-like protection system, in which China being the patron. And in this integration, Asia had long been quite developed part of the world. This was true at least till the outbreak of the Anglo-China war in 1830’s. In the above system, the main roles were played by the sates, and there was no such notion as the participation into politics in the part of the populace. For the populace, the states were merely parasitic burdens. Reflecting this, the intellectuals in Asia took the crucial roles in politics rather in religion
Leibniz’s Cultural Pluralism and Natural Law
4)This article was published at the same time on my website,its URL beeing(http://prof.mt.tama.hosei.ac.jp/~hhirano/).So, I write this abstruct in Japanese mostly. My articles preceeding and related this are article 1) and article 3). If interested, please read these Japanese articles, too.この論文は1)にはじまり3)に至った筆者の論旨を拡充し断定的に述べた英文論文である。西欧文化圏における「理性的文化一元論」に決して含まれなかった論客は、G.W. ライプニッツその人であった。この事実に注目しえていたのは20世紀ドイツの倫理学者アルベルト・ハイネカンプ等を除くとほとんど居ない。しかしライプニッツ思想が晩年に到達したこの側面はもっと注目されてよい。かえって『自然のフラクタル幾何学」で有名な数学者であるブノア・マンデルブロートのような論者の方が、かえってライプニッツの断片の中に散見される彼のこの「多元主義・相対主義」の思考様式に深い興味と関心を告白している。彼は単にニュートンと微分法の発見を争うだけの思想家ではないのである
Metal-free isotactic-specific radical polymerization of N-isopropylacrylamide with pyridine N-oxide derivatives : the effect of methyl substituents of pyridine N-oxide on the isotactic-specificity and the proposed mechanism for the isotactic-specific radical polymerization
The radical polymerizations of N-isopropylacrylamide (NIPAAm) in chloroform at low temperatures in the presence of pyridine N-oxide (PNO) derivatives were investigated. It was found that the methylation at meta-positions of PNO improved the isotactic-specificity induced by PNO, whereas the methylation at ortho-positions prevented the induction of the isotactic-specificity. NMR analysis revealed that NIPAAm and PNO derivatives formed predominantly 2:1 complex through a hydrogen bonding interaction. Furthermore, the induction of the isotactic-specificity was attributed to the conformationally-limited propagating radicals. Based on these findings, the mechanism of the isotactic-specific radical polymerization was discussed
Hydrogen-bond-assisted isotactic-specific radical polymerization of N-isopropylacrylamide with pyridine N-oxide
Radical polymerization of N-isopropylacrylamide (NIPAAm) in CHCl3 at low temperatures in the presence of pyridine N-oxide (PNO) was investigated. An isotactic poly(NIPAAm) with meso diad content of 61% was successfully prepared at –60°C in the presence of a twofold amount of PNO. Thermodynamic analysis suggested that the isotactic-specificity was entropically induced, probably due to conformational fixation near the propagating chain-end through coordination by PNO
Metal-free isotactic-specific radical polymerization of N-alkylacrylamides with 3,5-dimethylpyridine N-oxide : The effect of the N-substituent and solvent on the isotactic specificity
Radical polymerization of N-methylacrylamide (NMAAm), N-n-propylacrylamide, N-isopropylacrylamide (NIPAAm) and N-benzylacrylamide was investigated in CHCl3, CH2Cl2 and CH3CN, in the presence of 3,5-dimethylpyridine N-oxide (35DMPNO) to examine the effects of the N-substituent and the solvent on the isotactic specificity induced by 35DMPNO. With addition of 35DMPNO to radical polymerization of N-alkylacrylamides in CHCl3, isotactic specificity was significantly induced in NIPAAm polymerization but only slightly induced in NMAAm polymerization. Furthermore, mixed solvents of CH3CN and halomethanes such as CHCl3 and CH2Cl2 enhanced the ability of 35DMPNO to induce isotactic specificity, and poly(NIPAAm) with 74% meso dyad was obtained
Microfluidic cell engineering on high-density microelectrode arrays for assessing structure-function relationships in living neuronal networks
Neuronal networks in dissociated culture combined with cell engineering
technology offer a pivotal platform to constructively explore the relationship
between structure and function in living neuronal networks. Here, we fabricated
defined neuronal networks possessing a modular architecture on high-density
microelectrode arrays (HD-MEAs), a state-of-the-art electrophysiological tool
for recording neural activity with high spatial and temporal resolutions. We
first established a surface coating protocol using a cell-permissive hydrogel
to stably attach polydimethylsiloxane microfluidic film on the HD-MEA. We then
recorded the spontaneous neural activity of the engineered neuronal network,
which revealed an important portrait of the engineered neuronal
network--modular architecture enhances functional complexity by reducing the
excessive neural correlation between spatially segregated modules. The results
of this study highlight the impact of HD-MEA recordings combined with cell
engineering technologies as a novel tool in neuroscience to constructively
assess the structure-function relationships in neuronal networks.Comment: 18 pages, 5 figure
Suppression of hypersynchronous network activity in cultured cortical neurons using an ultrasoft silicone scaffold
The spontaneous activity pattern of cortical neurons in dissociated culture
is characterized by burst firing that is highly synchronized among a wide
population of cells. The degree of synchrony, however, is excessively higher
than that in cortical tissues. Here, we employed polydimethylsiloxane (PDMS)
elastomers to establish a novel system for culturing neurons on a scaffold with
an elastic modulus resembling brain tissue, and investigated the effect of the
scaffold's elasticity on network activity patterns in cultured rat cortical
neurons. Using whole-cell patch clamp to assess the scaffold effect on the
development of synaptic connections, we found that the amplitude of excitatory
postsynaptic current, as well as the frequency of spontaneous transmissions,
was reduced in neuronal networks grown on an ultrasoft PDMS with an elastic
modulus of 0.5 kPa. Furthermore, the ultrasoft scaffold was found to suppress
neural correlations in the spontaneous activity of the cultured neuronal
network. The dose of GsMTx-4, an antagonist of stretch-activated cation
channels (SACs), required to reduce the generation of the events below 1.0
event/min on PDMS substrates was lower than that for neurons on a glass
substrate. This suggests that the difference in the baseline level of SAC
activation is a molecular mechanism underlying the alteration in neuronal
network activity depending on scaffold stiffness. Our results demonstrate the
potential application of PDMS with biomimetic elasticity as cell-culture
scaffold for bridging the in vivo-in vitro gap in neuronal systems.Comment: 23 pages, 6 figure
Model-Free Idealization: Adaptive Integrated Approach for Idealization of Ion Channel Currents (AI2)
Single-channel electrophysiological recordings provide insights into
transmembrane ion permeation and channel gating mechanisms. The first step in
the analysis of the recorded currents involves an "idealization" process, in
which noisy raw data are classified into two discrete levels corresponding to
the open and closed states of channels. This provides valuable information on
the gating kinetics of ion channels. However, the idealization step is often
challenging in cases of currents with poor signal-to-noise ratios (SNR) and
baseline drifts, especially when the gating model of the target channel is not
identified. We report herein on a highly robust model-free idealization method
for achieving this goal. The algorithm, called AI2 (Adaptive Integrated
Approach for the Idealization of Ion Channel Currents), is composed of Kalman
filter and Gaussian Mixture Model (GMM) clustering and functions without user
input. AI2 automatically determines the noise reduction setting based on the
degree of separation between the open and closed levels. We validated the
method on pseudo-channel-current datasets which contain either computed or
experimentally recorded noise. The AI2 algorithm was then tested on actual
experimental data for biological channels including gramicidin A, a
voltage-gated sodium channel, and other unidentified channels. We compared the
idealization results with those obtained by the conventional methods, including
the 50%-threshold-crossing method
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